Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f436d3a7967e64d…

MALICIOUS

PDF

78.1 KB Created: 2021-07-21 19:30:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: cfcdb8d1d081adfb659d6e0bdc8eb9c4 SHA-1: 867bb938e937315d2f620aa975d1a135205ff0b0 SHA-256: 8f436d3a7967e64d2fb1975b4694a8a0aaf1a4b6b9de64eba056055870abd252
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites. Heuristics indicate this is a link farm designed to direct users to external content, likely for phishing or malware distribution. The ML classifier and ClamAV detection strongly support the malicious nature of this document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607be4867abaf---pumumabitedufam.pdf
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160bd53848b1b7---58517520447.pdf
    • http://tscyw.net/userfiles/file/20210705011607_rzgevp.pdf
    • http://n-production.com/upload/fckeditor/file/xidokevopupaj.pdf
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/275743bf178e4c703bac7b0a3c83dc5b/4339380106.pdf
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160946654b9c14---72486779208.pdf
    • http://daehwa.info/uploaded/file/75660736588.pdf
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607e49e42286f---49720285494.pdf
    • http://akpanlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/zexilifigudasesanugafuli.pdf
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/4a3935387751ae1371be532d30e13bf2/xonikulepenovagudizote.pdf
    • http://china-engine.net/ckfinder/userfiles/files/45651016151.pdf
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f093b7cdcd8---lawomevazipiwivik.pdf
    • http://restravel.ru/ckfinder/userfiles/files/baxukezajinuw.pdf
    • https://anzmrrn.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609ffd95edb78---zemoleziroxugelabox.pdf
    • http://mebco.ru/images/file/tewituvawimukarisadepuvax.pdf
    • https://cursosadistanciayonline.com/medios//files/lakibobosazebur.pdf
    • https://hotellemaritime.com/hotel/upload/files/papedaxalezasekukosero.pdf
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d825c2a04c---tuzedufanefibowuza.pdf
    • https://victorybear-info.com/userfiles/files/tomusawikugepuxoxesab.pdf
    • http://castanienfamily.com/clients/74558/File/vuzusokesewinori.pdf
    • https://pnp-studio.com/fckeditorfiles/file/86392526105.pdf
    • http://acecaalcoy.com/userfiles/file/61200586893.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=age+of+empires+full+game+download
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cc6c.bin
29575b6aaf6acc6ee125af818825e6681f918b0666c77c14d684190b5d40aacb
pdf-font-stream PDF embedded font (sfnt) at offset 0xCC6C 10912 bytes
font_01_sfnt_off0000e583.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE583 16792 bytes
font_02_sfnt_off0000fd95.bin
492add3f9d11330f51041be7e3a309f022eedc0a4afb5208ab617ea16a796485
pdf-font-stream PDF embedded font (sfnt) at offset 0xFD95 17208 bytes